Aggressive Chordomas: Clinical Outcome of 13 Patients

De novo Versus Secondary Dedifferentiated Chordomas: A Population-Based Analysis and Integrated Individual Participant Data Meta-Analysis

OBJECTIVE

There is a lack of data about the clinicopathological and molecular characteristics of de novo versus secondary dedifferentiated chordoma (DC). This integrated study aimed to investigate the similarities and differences in clinicopathological manifestations, prognoses, and molecular profiles of these 2 subtypes.

METHODS

We accessed the Surveillance, Epidemiology, and End Results (SEER) Program for DC cases from 1975 to 2020. Three electronic databases were also searched for additional DCs. Individual patient data of DC patients from SEER and published literature were combined in integrated analyses.

RESULTS

After excluding duplicated patients, we identified 14 and 116 DC patients from SEER and published literature, respectively. There were 74 de novo, 39 secondary, and 18 cases with unknown origin. Our results showed that de novo and secondary DCs were not statistically different in terms of age, gender, primary location, tumor size, distant metastasis at diagnosis, extent of resection, and chemotherapy receipt. There was limited available molecular data for de novo and secondary DCs, though examples TP53 mutations were found in both. In addition, the rates of tumor relapse, metastasis during follow-up, and patient mortality were also comparable between the 2 groups. In the multivariate Cox regression model, we demonstrated that gross total removal and radiotherapy use were associated with prolonged survival of DCs.

CONCLUSIONS

De novo and secondary DCs were statistically comparable in terms of patient demographics, clinical manifestations, and prognoses. Gross total excision and radiotherapy were optimal treatments associated with better outcomes of DC patients.

Surgical Management of Spinal Chordoma: A Systematic Review and Single-Center Experience

OBJECTIVE

Chordoma is a rare neoplasm of the neuraxis derived from remnants of the primitive notochord. The importance of wide margins and use of adjuvant therapy in spinal chordomas are still contentious points in the management of spinal chordomas. We conducted a systematic review of the surgical management of spinal chordomas alongside our 10-year institutional experience.

METHODS

A systematic search of the literature was performed in November 2020 using Embase and MEDLINE for articles regarding the surgical management of chordomas arising from the mobile spine and sacrum. We also searched for all adult patients who were surgically managed for spinal chordomas at our institute between 2010 and 2020. In both the systematic review and our institutional case series, data on adequacy of resection, use of adjuvant therapy, complications, recurrence (local or metastatic), and survival outcomes were collected.

RESULTS

We identified and analyzed 42 articles, yielding 1531 patients, from which the overall gross total or wide resection rate was 54.9%. Among the 8 cases in our institutional experience (4 sacral, 3 cervical, and 1 lumbar), we achieved gross total resection in 50% of initial operations. The recurrence rate was 25% in our gross total resection group and 50% where initial resection was subtotal. Of patients, 75% had no evidence of recurrence at most recent follow-up.

CONCLUSIONS

Albeit difficult at times because of the proximity to neurovascular tissue, achieving a wide resection followed by adjuvant therapy for spinal chordomas is of great importance. Multidisciplinary discussion is valuable to ensure the best outcome for the patient.

Clinicopathological and Prognostic Characteristics in Dedifferentiated/Poorly Differentiated Chordomas: A Pooled Analysis of Individual Patient Data From 58 Studies and Comparison With Conventional Chordomas

Background

Currently, the clinicopathological and prognostic characteristics of dedifferentiated chordoma (DC) and poorly differentiated chordoma (PDC) remain poorly understood. In this study, we sought to characterize clinicopathological parameters in a large PDC/DC cohort and determine their correlations with progression-free survival (PFS) and overall survival (OS) of patients. We also attempted to compare clinical features between PDC/DC and conventional chordoma (CC).

Methods

Literature searches (from inception to June 01, 2020) using Medline, Embase, Google Scholar and Wanfang databases were conducted to identify eligible studies according to predefined criteria. The local database at our center was also retrospectively reviewed to include CC patients for comparative analysis.

Results

Fifty-eight studies from the literature and 90 CC patients from our local institute were identified; in total, 54 PDC patients and 96 DC patients were analyzed. Overall, PDC or DC had distinct characteristics from CC, while PDC and DC shared similar clinical features. Adjuvant radiotherapy and chemotherapy were associated with both PFS and OS in PDC patients in the univariate and/or multivariate analyses. In the DC cohort, tumor resection type, adjuvant chemotherapy and tumor dedifferentiation components significantly affected PFS, whereas none of them were predictive of outcome in the multivariate analysis. By analyzing OS, we found that surgery, resection type and the time to dedifferentiation predicted the survival of DC patients; however, only surgery remained significant after adjusting for other covariables.

Conclusions

These data may offer useful information to better understand the clinical characteristics of PDC/DC and may be helpful in improving the outcome prediction of patients.

Dedifferentiated Chordoma: Clinicopathologic and Molecular Characteristics With Integrative Analysis

Dedifferentiated chordoma is a rare chordoma subtype characterized by a high-grade sarcoma juxtaposed to conventional chordoma. We identified a series of dedifferentiated chordomas, reviewed clinicopathologic features, performed next-generation sequencing in select cases, and analyzed all related English-language publications. Our series included 7 men and 3 women (age 15 to 80 y [median: 54 y]; <1% of >1000 chordomas surveyed). The tumor (2.8 to 24.5 cm [median: 5.8 cm] in size) presented de novo or as recurrence (including postradiotherapy) in sacrum (n=5), skull base (n=2), lumbar spine (n=1), thoracic/mediastinum (n=1), and lung (n=1; as metastasis). Histologically, the dedifferentiated component (3% to 95% [median: 60%]) was pleomorphic-to-fibrosarcomatous, juxtaposed to conventional (n=8) or chondroid (n=2) component. By immunohistochemistry, the conventional/chondroid component consistently expressed cytokeratin and brachyury, whereas the dedifferentiated component showed loss of both. We identified a sacral conventional chordoma with INI1 loss, with one of the lung metastases showing biphasic histology with loss of cytokeratin and brachyury in the dedifferentiated component. Sequencing identified tumor suppressor mutations in 4 tumors, including TP53 mutations in the dedifferentiated component in 3 tumors. Of 7 patients with follow-up, 6 developed metastases; 4 died at 15 to 99 months (median: 24 mo) after dedifferentiated chordoma diagnosis. Collectively, of 87 dedifferentiated chordoma patients described in 1913-2020 (including 10 herein), the median overall survival was 20 months. In summary, dedifferentiated chordoma involves diverse sites and presents de novo, postradiotherapy, or as recurrence/metastasis months-to-years after initial diagnosis. The dedifferentiated component shows loss of brachyury and cytokeratin staining and harbors recurrent TP53 mutations, implicating tumor suppressor dysregulation in chordoma dedifferentiation.

Predictive role of Apparent Diffusion Coefficient (ADC) from Diffusion Weighted MRI in patients with sacral chordoma treated with carbon ion radiotherapy (CIRT) alone

PURPOSE

To evaluate if baseline ADC from DWI sequences could predict response to treatment in patients with sacral chordoma not suitable for surgery treated with carbon ion radiotherapy (CIRT) alone compared with volume changes.

METHODS

Fifty-nine patients with sacral chordoma not suitable for surgery underwent one cycle of CIRT alone and a minimum of 12-months follow-up. All patients underwent MRI before treatment (baseline), every three months in the first two years after treatment, and every six months afterwards. For each MRI, lesion volume was obtained and median, kurtosis, and skewness ADC were analyzed within the whole lesion volume. Volume changes between baseline and the last available follow-up were used to divide patients with partial response, progression of disease and stable disease (PR, PD, and SD).

RESULTS

Ten patients were excluded since DWI sequences from baseline MRI were not available. ADC maps obtained from baseline DWI examinations of 50 lesions in the remaining 49 patients were considered. Seven lesions were categorized as PD, 30 PR, and 13 SD. PD showed significantly higher median ADC values at baseline (p = 0.003) compared with both PR and SD (1665vs1253vs1263 *10^-6 mm²/s), and more negative skewness values (-0.26vs0.26vs0.08), although not significantly different (p = 0.16).

CONCLUSIONS

Preliminary results suggest that baseline ADC could predict response to treatment with CIRT, particularly to detect potential non-responder patients.